Temperature difference of \(120^{\circ}C\) is maintained between two ends of a uniform rod \(AB\) of length \(2L\). Another bent rod \(PQ\), of same cross section as \(AB\) and length \(\frac{3L}{2}\) , is connected across \(AB\) (See figure). In steady state, temperature difference between \(P\) and \(Q\) will be close to :
- $60^{\circ} C$
- $75^{\circ} C$
- $35^{\circ} C$
- $45^{\circ} C$
The Correct Option is D
Solution and Explanation
\(\frac{\Delta T}{R_{eq}} = I = \frac{\left(120\right)5}{8R} = \frac{120\times5}{8R}\)
\(\Delta T_{PQ} = \frac{120 \times5}{8R} \times\frac{3}{5}R = \frac{360}{8} = 45^{\circ}C\)
\(\text{Hence, the correct option is (D):}\) \(45\degree\;C\)
Top Questions on Heat Transfer
- In the steady state of temperature, the flow of heat across the body depends upon its:
A. thermal capacity
B. thermal conductivity
C. temperature difference across its opposite faces
D. thermal resistivity
Choose the CORRECT answer from the options given below:- CUET (PG) - 2025
- Physics
- Heat Transfer
Match the LIST-I with LIST-II
LIST-I LIST-II (Type of Fouling) (Fouling Mechanism) A Precipitation IV Precipitation of dissolved substances... B Freezing III Solidification of Liquid components... C Particulate I Accumulation of fine particles suspended... D Corrosion II Heat transfer surface reacts with ambient... Identify the evaporator
- The difference between the initial and the final temperature divided by the freezing time is known as
- The Nusselt number is related to the Reynolds number in laminar and turbulent flows respectively as:
- CUET (PG) - 2025
- Mechanical Engineering
- Heat Transfer
Questions Asked in JEE Main exam
- Let \( f: \mathbb{R} \to \mathbb{R} \) be a function defined by \( f(x) = \left( 2 + 3a \right)x^2 + \left( \frac{a+2}{a-1} \right)x + b, a \neq 1 \). If \[ f(x + y) = f(x) + f(y) + 1 - \frac{2}{7}xy, \] then the value of \( 28 \sum_{i=1}^5 f(i) \) is:
- JEE Main - 2025
- Functions
Let $ f: \mathbb{R} \to \mathbb{R} $ be a twice differentiable function such that $$ f''(x)\sin\left(\frac{x}{2}\right) + f'(2x - 2y) = (\cos x)\sin(y + 2x) + f(2x - 2y) $$ for all $ x, y \in \mathbb{R} $. If $ f(0) = 1 $, then the value of $ 24f^{(4)}\left(\frac{5\pi}{3}\right) $ is:
- JEE Main - 2025
- Differential Calculus
- A 400 g solid cube having an edge of length \(10\) cm floats in water. How much volume of the cube is outside the water? (Given: density of water = \(1000 { kg/m}^3\))
- An infinite wire has a circular bend of radius \( a \), and carrying a current \( I \) as shown in the figure. The magnitude of the magnetic field at the origin \( O \) of the arc is given by:
- JEE Main - 2025
- Magnetic Field
- Let \( A = [a_{ij}] \) be a matrix of order 3 \(\times\) 3, with \(a_{ij} = (\sqrt{2})^{i+j}\). If the sum of all the elements in the third row of \( A^2 \) is \( \alpha + \beta\sqrt{2} \), where \(\alpha, \beta \in \mathbb{Z}\), then \(\alpha + \beta\) is equal to:
- JEE Main - 2025
- Matrices and Determinants
Concepts Used:
Heat Transfer
What is Heat Transfer?
It is defined as the movement of heat across the border of the system due to a difference in temperature between system and its surroundings.
How is Heat Transferred?
Heat can travel from one place to another in several ways. The different modes of heat transfer include:
- Conduction - Heat flows from things with higher temp to objects with lower temp.
- Convection - Movement of liquid molecules from higher temp regions to lower temp regions.
- Radiation - Radiant heat is present in every other way in our daily lives. Thermal radiations are also known to as radiant heat. Thermal radiation is generated by the emission of electromagnetic waves.
